Turbine rotor, manufacturing method thereof and steam turbine using turbine rotor

Abstract

A turbine rotor includes a high- and low-temperature side rotor base materials. The high- and low-temperature materials include concavities and grooves. The turbine rotor has an enclosed space formed by the concavity of the high- and low-temperature materials being disposed opposingly, and a gap formed by the grooves of the high- and low-temperature materials being disposed opposingly. The turbine rotor contains a buildup welding section formed between the high- and low-temperature materials, which has the same composition as that of the high- or low-temperature material, and has a penetration bead on the enclosed space side, and the gap contains a weld metal filled therein. Thus, a stable penetration bead can be formed in a dissimilar material welded rotor combining two kinds of alloy materials with different thermal properties, and then generation of a non-welded portion of a butting section that becomes a start point of fracture can be suppressed.

What is claimed is: 
     
       1. A turbine rotor comprising:
 a high temperature side rotor base material; and 
 a low temperature side rotor base material, 
 the high temperature side rotor base material and the low temperature side rotor base material respectively including concavities and grooves, 
 the turbine rotor having an enclosed space section formed by the concavity of the high temperature side rotor base material and the concavity of the low temperature side rotor base material being disposed opposingly, and a gap formed by the groove of the high temperature side rotor base material and the groove of the low temperature side rotor base material being disposed opposingly, 
 the turbine rotor containing a buildup welding section formed between the high temperature side rotor base material and the low temperature side rotor base material, 
 wherein the buildup welding section has the same composition as that of the high temperature side rotor base material or the low temperature side rotor base material, and has a penetration bead on the enclosed space section side, and the gap contains a weld metal filled therein; and 
 wherein a ratio of a thermal conductivity of the high temperature side rotor base material and the low temperature side rotor base material is in the range of 2/3 to 3/2. 
 
     
     
       2. The turbine rotor according to  claim 1 ,
 wherein the high temperature side rotor base material has an entire surface buttering section on a surface of the groove. 
 
     
     
       3. The turbine rotor according to  claim 1 ,
 wherein the high temperature side rotor base material is of a nickel-based alloy consisting of 
 cobalt (Co): 5 to 15 mass %; 
 chromium (Cr): 13 to 15.5 mass %; 
 aluminum (Al): 4.0 to 5.5 mass %; 
 titanium (Ti): 0.1 to 2.0 mass %; 
 niobium (Nb): 0.1 to 1.0 mass %; 
 tantalum (Ta): 0.1 to 3.0 mass %; 
 molybdenum (Mo): 0.1 to 2.0 mass %; 
 tungsten (W): 4.5 to 10 mass %; 
 hafnium (Hf): 0.1 to 2.0 mass %; 
 carbon (C): 0.05 to 0.20 mass %; 
 boron (B): 0.001 to 0.03 mass %; and 
 zirconium (Zr): 0.01 to 0.1 mass %, with the balance being nickel (Ni) and unavoidable impurities. 
 
     
     
       4. The turbine rotor according to  claim 1 ,
 wherein the low temperature side rotor base material is of 12% chromium steel having a totally tempered martensitic structure containing 
 carbon (C): 0.1 to 0.2 mass %; 
 manganese (Mn): 0.3 to 1.0 mass %; 
 nickel (Ni): 1 mass % or less; 
 chromium (Cr): 9 to 13 mass %; 
 molybdenum (Mo): 0.1 to 1.5 mass %; 
 tungsten (W): 0.2 to 5.0 mass %; 
 niobium (Nb): 0.02 to 0.1 mass %; and 
 cobalt (Co): 3 mass % or less. 
 
     
     
       5. The turbine rotor according to  claim 1 ,
 wherein the low temperature side rotor base material is of 1% chromium-molybdenum-vanadium steel having a bainitic structure containing 
 carbon (C): 0.25 to 0.35 mass %; 
 manganese (Mn): 0.5 to 1 mass %; 
 nickel (Ni): 1 mass % or less; 
 chromium (Cr): 0.8 to 1.5 mass %; 
 molybdenum (Mo): 1.0 to 1.5 mass %; and 
 vanadium (V): 0.2 to 0.3 mass %. 
 
     
     
       6. The turbine rotor according to  claim 1 ,
 wherein the high temperature side rotor base material is of a nickel-based alloy consisting of 
 cobalt (Co): 5 to 15 mass %; 
 chromium (Cr): 13 to 15.5 mass %; 
 aluminum (Al): 4.0 to 5.5 mass %; 
 titanium (Ti): 0.1 to 2.0 mass %; 
 niobium (Nb): 0.1 to 1.0 mass %; 
 tantalum (Ta): 0.1 to 3.0 mass %; 
 molybdenum (Mo): 0.1 to 2.0 mass %; 
 tungsten (W): 4.5 to 10 mass %; 
 hafnium (Hf): 0.1 to 2.0 mass %; 
 carbon (C): 0.05 to 0.20 mass %; 
 boron (B): 0.001 to 0.03 mass %; and 
 zirconium (Zr): 0.01 to 0.1 mass %, with the balance being nickel (Ni) and unavoidable impurities, and 
 the low temperature side rotor base material is of 12% chromium steel having a totally tempered martensitic structure containing 
 carbon (C): 0.1 to 0.2 mass %; 
 manganese (Mn): 0.3 to 1.0 mass %; 
 nickel (Ni): 1 mass % or less; 
 chromium (Cr): 9 to 13 mass %; 
 molybdenum (Mo): 0.1 to 1.5 mass %; 
 tungsten (W): 0.2 to 5.0 mass %; 
 niobium (Nb): 0.02 to 0.1 mass %; and 
 cobalt (Co): 3 mass % or less, 
 or of 1% chromium-molybdenum-vanadium steel having a bainitic structure containing 
 carbon (C): 0.25 to 0.35 mass %; 
 manganese (Mn): 0.5 to 1 mass %; 
 nickel (Ni): 1 mass % or less; 
 chromium (Cr): 0.8 to 1.5 mass %; 
 molybdenum (Mo): 1.0 to 1.5 mass %; and 
 vanadium (V): 0.2 to 0.3 mass %. 
 
     
     
       7. The turbine rotor according to  claim 1 ,
 wherein the high temperature side rotor base material is of a nickel-based alloy consisting of 
 cobalt (Co): 5 to 15 mass %; 
 chromium (Cr): 13 to 15.5 mass %; 
 aluminum (Al): 4.0 to 5.5 mass %; 
 titanium (Ti): 0.1 to 2.0 mass %; 
 niobium (Nb): 0.1 to 1.0 mass %; 
 tantalum (Ta): 0.1 to 3.0 mass %; 
 molybdenum (Mo): 0.1 to 2.0 mass %; 
 tungsten (W): 4.5 to 10 mass %; 
 hafnium (Hf): 0.1 to 2.0 mass %; 
 carbon (C): 0.05 to 0.20 mass %; 
 boron (B): 0.001 to 0.03 mass %; and 
 zirconium (Zr): 0.01 to 0.1 mass %, with the balance being nickel (Ni) and unavoidable impurities; and 
 the low temperature side rotor base material is of 12% chromium steel having a totally tempered martensitic structure containing 
 carbon (C): 0.1 to 0.2 mass %; 
 manganese (Mn): 0.3 to 1.0 mass %; 
 nickel (Ni): 1 mass % or less; 
 chromium (Cr): 9 to 13 mass %; 
 molybdenum (Mo): 0.1 to 1.5 mass %; 
 tungsten (W): 0.2 to 5.0 mass %; 
 niobium (Nb): 0.02 to 0.1 mass %; and 
 cobalt (Co): 3 mass % or less. 
 
     
     
       8. The turbine rotor according to  claim 1 ,
 wherein the high temperature side rotor base material is of a nickel-based alloy consisting of 
 cobalt (Co): 5 to 15 mass %; 
 chromium (Cr): 13 to 15.5 mass %; 
 aluminum (Al): 4.0 to 5.5 mass %; 
 titanium (Ti): 0.1 to 2.0 mass %; 
 niobium (Nb): 0.1 to 1.0 mass %; 
 tantalum (Ta): 0.1 to 3.0 mass %; 
 molybdenum (Mo): 0.1 to 2.0 mass %; 
 tungsten (W): 4.5 to 10 mass %; 
 hafnium (Hf): 0.1 to 2.0 mass %; 
 carbon (C): 0.05 to 0.20 mass %; 
 boron (B): 0.001 to 0.03 mass %; and 
 zirconium (Zr): 0.01 to 0.1 mass %, with the balance being nickel (Ni) and unavoidable impurities, 
 or of a nickel-iron-based alloy consisting of 
 iron (Fe): 30 to 40 mass %; 
 chromium (Cr): 14 to 16 mass %; 
 titanium (Ti): 1.2 to 1.7 mass %; 
 aluminum (Al): 1.1 to 1.5 mass %; 
 niobium (Nb): 1.9 to 2.7 mass %; and 
 carbon (C): 0.05 mass % or less; with the balance being nickel (Ni) and unavoidable impurities, and 
 the low temperature side rotor base material is of 12% chromium steel having a totally tempered martensitic structure containing 
 carbon (C): 0.1 to 0.2 mass %; 
 manganese (Mn): 0.3 to 1.0 mass %; 
 nickel (Ni): 1 mass % or less; 
 chromium (Cr): 9 to 13 mass %; 
 molybdenum (Mo): 0.1 to 1.5 mass %; 
 tungsten (W): 0.2 to 5.0 mass %; 
 niobium (Nb): 0.02 to 0.1 mass %; and 
 cobalt (Co): 3 mass % or less, 
 or of 1% chromium-molybdenum-vanadium steel having a bainitic structure containing 
 carbon (C): 0.25 to 0.35 mass %; 
 manganese (Mn): 0.5 to 1 mass %; 
 nickel (Ni): 1 mass % or less; 
 chromium (Cr): 0.8 to 1.5 mass %; 
 molybdenum (Mo): 1.0 to 1.5 mass %; and 
 vanadium (V): 0.2 to 0.3 mass %. 
 
     
     
       9. The turbine rotor according to  claim 1 ,
 wherein the high temperature side rotor base material is of a nickel-based alloy consisting of 
 cobalt (Co): 5 to 15 mass %; 
 chromium (Cr): 13 to 15.5 mass %; 
 aluminum (Al): 4.0 to 5.5 mass %; 
 titanium (Ti): 0.1 to 2.0 mass %; 
 niobium (Nb): 0.1 to 1.0 mass %; 
 tantalum (Ta): 0.1 to 3.0 mass %; 
 molybdenum (Mo): 0.1 to 2.0 mass %; 
 tungsten (W): 4.5 to 10 mass %; 
 hafnium (Hf): 0.1 to 2.0 mass %; 
 carbon (C): 0.05 to 0.20 mass %; 
 boron (B): 0.001 to 0.03 mass %; and 
 zirconium (Zr): 0.01 to 0.1 mass %, with the balance being nickel (Ni) and unavoidable impurities, 
 or of a nickel-iron-based alloy consisting of 
 iron (Fe): 30 to 40 mass %; 
 chromium (Cr): 14 to 16 mass %; 
 titanium (Ti): 1.2 to 1.7 mass %; 
 aluminum (Al): 1.1 to 1.5 mass %; 
 niobium (Nb): 1.9 to 2.7 mass %; and 
 carbon (C): 0.05 mass % or less; with the balance being nickel (Ni) and unavoidable impurities, and 
 the low temperature side rotor base material is of 12% chromium steel having a totally tempered martensitic structure containing 
 carbon (C): 0.1 to 0.2 mass %; 
 manganese (Mn): 0.3 to 1.0 mass %; 
 nickel (Ni): 1 mass % or less; 
 chromium (Cr): 9 to 13 mass %; 
 molybdenum (Mo): 0.1 to 1.5 mass %; 
 tungsten (W): 0.2 to 5.0 mass %; 
 niobium (Nb): 0.02 to 0.1 mass %; and 
 cobalt (Co): 3 mass % or less. 
 
     
     
       10. A steam turbine including the turbine rotor according to  claim 1 . 
     
     
       11. A turbine rotor comprising:
 a high temperature side rotor base material; and 
 a low temperature side rotor base material, 
 the high temperature side rotor base material and the low temperature side rotor base material respectively including concavities and grooves, 
 the turbine rotor having an enclosed space section formed by the concavity of the high temperature side rotor base material and the concavity of the low temperature side rotor base material being disposed opposingly, and a gap formed by the groove of the high temperature side rotor base material and the groove of the low temperature side rotor base material being disposed opposingly, 
 the turbine rotor containing a buildup welding section formed between the high temperature side rotor base material and the low temperature side rotor base material, 
 wherein the buildup welding section has the same composition as that of the high temperature side rotor base material or the low temperature side rotor base material, and has a penetration bead on the enclosed space section side, and the gap contains a weld metal filled therein; and 
 wherein the high temperature side rotor base material is of a nickel-iron-based alloy consisting of 
 iron (Fe): 30 to 40 mass %; 
 chromium (Cr): 14 to 16 mass %; 
 titanium (Ti): 1.2 to 1.7 mass %; 
 aluminum (Al): 1.1 to 1.5 mass %; 
 niobium (Nb): 1.9 to 2.7 mass %; and 
 carbon (C): 0.05 mass % or less; with the balance being nickel (Ni) and unavoidable impurities. 
 
     
     
       12. A manufacturing method of a turbine rotor which includes:
 a high temperature side rotor base material; and 
 a low temperature side rotor base material, 
 the high temperature side rotor base material and the low temperature side rotor base material respectively including concavities and grooves, 
 the turbine rotor having an enclosed space section formed by the concavity of the high temperature side rotor base material and the concavity of the low temperature side rotor base material being disposed opposingly, and a gap formed by the groove of the high temperature side rotor base material and the groove of the low temperature side rotor base material being disposed opposingly, 
 the manufacturing method comprising the steps of: 
 a buttering buildup step for subjecting a butting section of the high temperature side rotor base material or the low temperature side rotor base material to buttering buildup; 
 a penetration bead forming step for fusing the butting section and forming the penetration bead; 
 a regular welding step for filling the gap with the weld metal; and 
 wherein a ratio of a thermal conductivity of the high temperature side rotor base material and the low temperature side rotor base material is in the range of 2/3 to 3/2. 
 
     
     
       13. The manufacturing method according to  claim 12 , further comprising
 a groove working step for subjecting the high temperature side rotor base material and the low temperature side rotor base material to groove work after the buttering buildup step, 
 the penetration bead forming step executed thereafter. 
 
     
     
       14. The manufacturing method according to  claim 12 , further comprising
 a buttering step for forming an entire surface buttering section on a surface of the groove of the high temperature side rotor base material before the buttering buildup step.